I just wanted to thank you all for the advise while I was putting my engine and trans. back in my 26 roadster. It turned out pretty good. Engine is a little tight but seems to be freeing up. I put about 10 miles on it today without any problems. My engine now has a scat crank, Aluminum pistons, 280 cam, along with the .009 distributor and model A carb that it had before. It runs really good. Good power but I get some vibration over 40 mph maybe from the drive shaft? I have to remember that I still have 20 mph brakes and steering. I hope I now have a drive train that will out last me. Anyway thanks a lot.

With only 10 miles on a fresh, tight motor, try to keep your speed down a bit. More like 25 - 30 until it's broken in more.

It's not entirely abnormal for a T motor to go through a vibration node over 40 mph. Although I would expect a Scat crank to change that "rule" significantly.

Unless the transmission was balanced, then assembled to the crank and the whole assembly checked for balance, then there is still a possibility for vibration in the drive line. Consider that the majority of T's on the road don't have any of those components balanced. Just enjoy the ride. Congrats and good luck.

Yep enjoy the ride. That's the plan.

Some vibrations are not in the engine, but parts such as fenders and splash aprons or hood. Or even the choke rod. Good to rule out everything else before blaming it on the engine.
Norm

Balancing the flywheel, transmission and trueing the transmission can make more difference on vibration than engine balance. This all depends on how far things are out of balance or run out. I have found the transmission shaft alone to run out .007". The flywheel and triple gears are big players on balancing. Static balancing seems to work well for model T's.

The tin shed did the trans and balanced everything.